Voice coil motor

ABSTRACT

A VCM (voice coil motor) is disclosed, the VCM including: a rotor including a cylindrical bobbin for accommodating a lens and protruded at a bottom end with a boss, and a coil block arranged at a periphery of the bobbin; a stator including a magnet facing the coil block and a yoke fixing the magnet; and an elastic member including a first elastic member formed with a through hole coupled to the boss of the bobbin and a second elastic member coupled to an upper end facing the bottom end of the bobbin; wherein the boss is formed with a disengagement prevention unit preventing the first elastic member from being disengaged from the boss, and the first elastic member is formed with a coupling unit contacting a joint where the disengagement prevention unit and the coupling unit meet.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/597,913, filed May 17, 2017; which is a continuation of U.S.application Ser. No. 15/010,680, filed Jan. 29, 2016, now U.S. Pat. No.9,658,425, issued May 23, 2017; which is a continuation of U.S.application Ser. No. 14/333,297, filed Jul. 16, 2014, now U.S. Pat. No.9,250,415, issued Feb. 2, 2016; which is a continuation of U.S.application Ser. No. 13/180,869, filed Jul. 12, 2011, now U.S. Pat. No.8,810,936, issued Aug. 19, 2014; which claims the benefit under 35U.S.C. § 119 of Korean Patent Application Nos. 10-2010-0067051, filedJul. 12, 2010; 10-2010-0071326, filed Jul. 23, 2010; 10-2010-0071635,filed Jul. 23, 2010; and 10-2010-0102737, filed Oct. 21, 2010, which arehereby incorporated by reference in their entirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates to a voice coil motor.

Description of the Related Art

Recently, a small optical device such as a super-small digital camera ona mobile phone or a high resolution digital camera has been developedand is formed with an actuator for adjusting magnification and focus.The camera on the mobile phone or the digital camera recently employs anactuator such as a VCM (voice coil motor) on a wide range base.

The conventional super-small digital camera on the mobile phone is suchthat it is impossible to adjust a gap between an image sensor and lens,and a lens driving device such as a VCM for adjusting the gap betweenthe image sensor and the lens has been developed to allow thesuper-small digital camera to capture an improved image.

The VCM is a motor that uses a force from a magnetic field generated bya magnet and a magnetic field generated by a coil block facing themagnet, such that the VCM is adequate in adjusting a gap between a lensand an image sensor in a camera module to enable obtainment of animproved image from the mobile phone.

A conventional VCM employed for the super-small digital camera used tobe unable to adjust a gap between a lens condensing outside light and animage sensor converting the outside light to an image.

The conventional VCM includes a cylindrical bobbin mounted therein witha lens, a coil block wound with a coil at a periphery of the bobbin, andan elastic member elastically supporting a magnet opposite to the coilblock and the bobbin.

The elastic member is coupled to a boss protruded from a bottom distalend of the bobbin, where the bobbin is moved upwards by a forcegenerated by a magnetic field generated by the coil, and the elasticmember elastically supports the bobbin.

However, the conventional VCM suffers from disadvantages in that a gapis frequently generated between the bobbin and the elastic memberarranged under the bobbin by a manufacturing tolerance of the bobbin andthe elastic member, and it is difficult to accurately adjust an intervalbetween a lens and an image sensor due to the gap between the bobbin andthe elastic member arranged under the bobbin.

Meantime, a part of a leaf spring is coupled to the bobbin by way ofinsert method, and to be more specific, the part of the leaf spring isinjected along with the bobbin to couple the bobbin to the leaf springwhen the bobbin is injected.

Alternatively, a boss formed at a distal end of the bobbin is coupled tothe leaf spring, and the leaf spring coupled to the boss is coupled tothe distal end of the bobbin by way of thermal fusion method.

In a case the part of the leaf spring is coupled to the bobbin by way ofinsert method according to the prior art, a manufacturing processbecomes complicated to increase a manufacturing cost, and in a case theleaf spring is inserted into the bobbin to deform the leaf spring, theleaf spring and the bobbin are disadvantageously disposed of altogether.

Another disadvantage is that in a case the leaf spring is coupled to thebobbin by the thermal fusion method, the leaf spring is disengaged fromthe bobbin due to vibration and/or shock applied from outside, becausean attachment strength between the bobbin and the leaf spring is smallerthan that of the insert method.

Alternatively, an adhesive is coated between a distal end of the bobbinand the leaf spring to increase a coupling strength between the bobbinand the leaf spring. However, another disadvantage is generated that itis difficult to improve a coupling strength between the bobbin and theleaf spring due to smaller adhesive coated area between the leaf springand the bobbin.

Still another disadvantage is that the coil electrically connected tothe leaf spring is short-circuited due to the leaf spring beingdisengaged from the bobbin.

Still further disadvantage is that the bobbin and the leaf spring aremutually bonded by an adhesive, and in a case the bobbin and the leafspring are bonded by the adhesive provided by a dispenser, the leafspring is separated along with the dispenser when the leaf spring isseparated after the adhesive is coated to the leaf spring using thedispenser, to damage the leaf spring and/or cause an adhesiveimperfection to the bobbin and the leaf spring.

BRIEF SUMMARY

The present disclosure is directed to cope with the abovementionedproblems and to provide a VCM (voice coil motor) configured to remove agap generated between a bobbin and an elastic member to accuratelyadjust an interval between a lens and an image sensor.

The present disclosure is to provide a VCM configured to increasereliability by reducing a manufacturing cost and preventing an elasticmember arranged on a distal end of a bobbin from being disengaged fromthe distal end of the bobbin by a shock or a vibration applied fromoutside.

The present disclosure is to provide a VCM configured to enhance acoupling power of an elastic member between a coil forming a coil blockarranged on a periphery of a bobbin and an elastic member electricallyconnected to the coil.

Technical problems to be solved by the present disclosure are notrestricted to the abovementioned description, and any other technicalproblems not mentioned so far will be clearly appreciated from thefollowing description by the skilled in the art.

In one general aspect of the present disclosure, there is provided avoice coil motor comprising: a base; a yoke disposed over the base; abobbin disposed inside the yoke and including a first protrusion unit ata lower portion and a second protrusion unit at an upper portion; a coilblock disposed on a side surface of the bobbin; a magnet facing the coilblock and secured at the yoke; an upper elastic member coupled to theupper portion of the bobbin and including an outer unit, an inner unitand a connection unit; and a lower elastic member coupled to the lowerportion of the bobbin, wherein the lower elastic member includes a firstspring and a second spring separated from the first spring, and each ofthe first and second springs includes an outer unit, an inner unit and aconnection unit, respectively, wherein a portion of each outer unit ofthe first and second springs is bent to form a terminal, wherein aportion of each inner unit of the first and second springs includes afirst through hole corresponding to the first protrusion unit, wherein aportion of the inner unit of the upper elastic member includes a secondthrough hole corresponding to the second protrusion unit, and whereinthe first protrusion unit is positioned at a location corresponding tothe first through hole, and the second protrusion unit is positioned ata location corresponding to the second through hole.

The voice coil motor according to the present disclosure has anadvantageous effect in that the adhesive guide lugs are formed at thebobbin coupled to the elastic member to prevent the elastic member frombeing deformed and damaged.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the present disclosure and are incorporated in thepresent disclosure and constitute a part of this application, andtogether with the description, serve to explain the principle of thedisclosure. In the drawings:

FIG. 1 is an exploded perspective view illustrating a VCM according toan exemplary embodiment of the present disclosure;

FIG. 2 is a cross-sectional view of a VCM of FIG. 1;

FIG. 3 is a partially enlarged view of ‘A’ of FIG. 2;

FIG. 4 is a plane view illustrating a surrounding of a through hole of afirst elastic member;

FIG. 5 is a cross-sectional view illustrating a first elastic member anda boss of a VCM according to another exemplary embodiment of the presentdisclosure;

FIG. 6 is a cross-sectional view illustrating a first elastic member anda boss of a VCM according to still another exemplary embodiment of thepresent disclosure;

FIG. 7 is a cross-sectional view illustrating a first elastic member anda boss of a VCM according to still another exemplary embodiment of thepresent disclosure;

FIG. 8 is a plane view illustrating a first elastic member of a VCMaccording to still another exemplary embodiment of the presentdisclosure;

FIG. 9 is a cross-sectional view illustrating a first elastic member anda heat-fused disengagement prevention unit of FIG. 8;

FIG. 10 is a cross-sectional view illustrating a disengagementprevention unit formed with a boss coupled to the first elastic memberand an adhesive of FIG. 8;

FIG. 11 is an exploded perspective view of a VCM according to anexemplary embodiment of the present disclosure;

FIG. 12 is a cross-sectional view of a VCM illustrated in FIG. 11;

FIG. 13 is a plane view illustrating a rear surface of a bobbin of FIG.11;

FIG. 14 is a plane view illustrating a first elastic member of FIG. 11;

FIG. 15 is a cross-sectional view illustrating a state in which thebobbin and the first elastic member of FIG. 11;

FIG. 16 is a cross-sectional view illustrating a state in which a bobbinand a first elastic member of a VCM according to another exemplaryembodiment of the present disclosure;

FIG. 17 is a cross-sectional view illustrating a state in which a bobbinand a first elastic member of a VCM according to still another exemplaryembodiment of the present disclosure;

FIG. 18 is an exploded perspective view of a VCM according to anexemplary embodiment of the present disclosure;

FIG. 19 is a plane view illustrating a first elastic member of FIG. 17;

FIG. 20 is a rear perspective view illustrating the bobbin and the firstelastic member of the elastic member of FIG. 17;

FIG. 21 is a partially enlarged view of ‘A’ of FIG. 20;

FIG. 22 is a partially cut-out perspective view of a VCM according to anexemplary embodiment of the present disclosure;

FIG. 23 is a perspective view illustrating the bobbin and elastic memberof FIG. 22;

FIG. 24 is a partially enlarged view of ‘A’ of FIG. 22; and

FIG. 25 is a cross-sectional view illustrating a process in which abobbin and an elastic member are bonded.

DETAILED DESCRIPTION

Advantages and features of the present invention may be understood morereadily by reference to the following detailed description of exemplaryembodiments and the accompanying drawings. Detailed descriptions ofwell-known functions, configurations or constructions are omitted forbrevity and clarity so as not to obscure the description of the presentdisclosure with unnecessary detail. Thus, the present disclosure is notlimited to the exemplary embodiments which will be described below, butmay be implemented in other forms. In the drawings, the width, length,thickness, etc. of components may be exaggerated or reduced for the sakeof convenience. Furthermore, throughout the descriptions, the samereference numerals will be assigned to the same elements in theexplanations of the figures, and explanations that duplicate one anotherwill be omitted. Accordingly, the meaning of specific terms or wordsused in the specification and claims should not be limited to theliteral or commonly employed sense, but should be construed or may bedifferent in accordance with the intention of a user or an operator andcustomary usages. Therefore, the definition of the specific terms orwords should be based on the contents across the specification.

The terms “first,” “second,” and the like, herein do not denote anyorder, quantity, or importance, but rather are used to distinguish oneelement from another, and the terms “a” and “an” herein do not denote alimitation of quantity, but rather denote the presence of at least oneof the referenced item.

As may be used herein, the terms “substantially” and “approximately”provide an industry-accepted tolerance for its corresponding term and/orrelativity between items. Such an industry-accepted tolerance rangesfrom less than one percent to ten percent and corresponds to, but is notlimited to, component values, angles, et cetera. Such relativity betweenitems ranges from less than one percent to ten percent.

FIG. 1 is an exploded perspective view illustrating a VCM according toan exemplary embodiment of the present disclosure, and FIG. 2 is across-sectional view of a VCM of FIG. 1.

Referring to FIGS. 1 and 2, a VCM (800) includes a rotor (100), anelastic member (200), a stator (300), a case (400) and a base (600). Therotor (100) includes a bobbin (150) and a coil block (190).

The bobbin (150) takes the shape of hollow holed cylinder foraccommodating a lens therein, for example. The cylindrical bobbin (150)includes an upper surface (120) and a bottom surface (130) opposite tothe upper surface (120).

An inner surface of the bobbin (150) for accommodating the lens isformed with a female screw unit to which a lens fixing member (notshown) is coupled, and the lens fixing member is coupled to the lens.Alternatively, it should be also appreciated that the lens is directlycoupled to the female screw unit of the bobbin (150).

A peripheral bottom distal end of the bobbin (150) is formed with a sill(115) for supporting a coil block (190, described later).

The coil block (190) of the rotor (100) is arranged on the hitching sill(115) formed at the bobbin (150), and takes the shape of a cylinderwound by a coil, for example. The coil block (190) may be directly woundon the periphery of the bobbin (150), or may be attached to theperiphery of the bobbin (150) by an adhesive after being wound in thecylindrical shape.

The stator (300) includes a yoke (310) and a magnet (350). The yoke(310) includes an upper plate (312), a lateral plate (314) and a yokeunit (316). The upper plate (312) of the yoke (310) may take the shapeof a square plate, when viewed from a top plan view, and is centrallyformed with a circular opening for exposing the upper distal end of thebobbin (150).

The lateral plate (314) is extended to a direction parallel with theperiphery of the bobbin (150) from four edges of the upper plate (312),and integrally formed with the four edges of upper plate (312). The yokeunit (316) is extended from an inner lateral surface of the upper plate(312) formed by the circular opening of the upper plate (312) to adirection facing the bottom distal end of the bobbin (150). The yokeunit (316) is inserted into a space formed by the bobbin (150) and thecoil block (190).

Magnets (350) are arranged at an inner space formed by the upper plate(312) of the yoke (310) and the lateral plate (314). Each magnet (350)is arranged on a position corresponding to that of the yoke unit (316)of the yoke (310), and each magnet (350) faces the coil block (190).

The bobbin (150) is moved upwards by a force generated by magnetic fieldgenerated by the magnets (350) and a magnetic field generated by thecoil block (190), and the bobbin (150) is elastically supported by firstand second elastic members (210, 220). At this time, a moved distance ofthe bobbin (150) can be accurately adjusted by a current applied to thecoil block (190).

A case (400) includes an upper case (410) and a bottom case (420). Theupper case (410) includes an upper plate (411) and a coupling pillar(412). The upper case (410) is arranged on an upper surface of the yoke(310), and the second elastic member (220, described later) in theelastic member (200) is interposed between the upper case (410) and theyoke (310).

The upper plate (411) of the upper case (410) takes the shape of asquare plate when viewed from a top plan view, and is centrally formedwith a circular opening (414) for exposing the bobbin (150).

The coupling pillar (412) is protruded in parallel with the bobbin (150)from four corners of the upper plate (411), and is coupled to the bottomcase (420, described later). The bottom case (420) includes pillars(425) coupled to each coupling pillar (412) of the upper case (410).

FIG. 3 is a partially enlarged view of ‘A’ of FIG. 2, and FIG. 4 is aplane view illustrating a surrounding of a through hole of a firstelastic member.

Referring to FIGS. 1, 3 and 4, the elastic member (200) in the presentexemplary embodiment of the present disclosure includes a first elasticmember (210) and a second elastic member (220). The first and secondelastic members (210, 220) may be leaf springs, each having a thinthickness, for example.

The first elastic member (210) is coupled to a bottom surface (130) ofthe bobbin (150). The first elastic member (210) includes two members,for example, and each first elastic member (210) is formed with athrough hole (212) for being coupled to a boss (132) formed at thebottom surface (130) of the bobbin (150). The first elastic member (210)is coupled to the boss (132) of the bobbin (150) through the throughhole (212), and the boss (132) of the bobbin (150) is formed with adisengagement prevention unit (134) for preventing the first elasticmember (210) coupled to the boss (132) of the bobbin (150) from beingdisengaged to outside of the boss (132) of the bobbin (150).

The disengagement prevention unit (134) is formed at an upper distal endof the boss (132) of the bobbin (150), takes the shape of a round headand is formed by applying heat and pressure to the distal end of theboss (132) of the bobbin (150). The disengagement prevention unit (134)includes a round head-shaped curvature unit (134 a), and a planar unit(134 b, or planar surface) opposite to the bottom surface (130) of thebobbin (150). A gap (G) is formed between the bottom surface (130) ofthe bobbin (150) and the planar unit (134 b).

In the exemplary embodiment of the present disclosure, in a case the gap(G) formed between the bottom surface (130) of the bobbin (150) and theplanar unit (134 b) is substantially same as thickness of the firstelastic member (210), the first elastic member (210) is not disengagedfrom the bottom surface (130) of the bobbin (150) but tightly contactedto the bottom surface (130) of the bobbin (150).

The gap (G) formed between the bottom surface (130) of the bobbin (150)and the planar surface (134 b) of the disengagement prevention unit(134) is formed to be larger than the thickness of the first elasticmember (210) due to various reasons including a manufacturing tolerancethat is generated in the course of manufacturing a very small size ofboss (132) of the bobbin (150), or a manufacturing tolerance that isgenerated in the course of forming the disengagement prevention unit(134) on the boss (132) of the bobbin (150) in a very small size.

In a case the gap (G) formed between the bottom surface (130) of thebobbin (150) and the planar unit (134 b) of the disengagement preventionunit (134) is formed to be larger than the thickness of the firstelastic member (210), the first elastic member (210) moves between thebottom surface (130) of the bobbin (150) and the planar surface (134 b).In a case the first elastic member (210) moves between the bottomsurface (130) of the bobbin (150) and the planar surface (134 b),performance of adjusting a distance between the image sensor and thelens can be greatly decreased by the VCM (800).

In the exemplary embodiment of the present disclosure, even if the gap(G) formed between the bottom surface (130) of the bobbin (150) and theplanar unit (134 b) of the disengagement prevention unit (134) is formedto be larger than the thickness of the first elastic member (210), thefirst elastic member (210) is made to be tightly brought into contactwith the bottom surface (130) of the bobbin (150).

The first elastic member (210) is formed with a plurality of cut-outunits (214) connected to a through hole (212) in order to couple thefirst elastic member (210) to the boss (132) of the bobbin (150) formedat the bottom surface (130) of the bobbin (150) using the through hole(212) of the first elastic member (210).

In the exemplary embodiment of the present disclosure, the through hole(212) is smaller in diameter than that of the boss (132) of the bobbin(150), and the diameter of the boss (132) of the bobbin (150) is formedto be smaller than a sum in which a length (L) of the cut-out unit (214)and a radius (r) of the through hole (212) are added up.

The plurality of cut-out units (214) is radially formed at the firstelastic member (210) about the through hole (212) of the first elasticmember (210). Hereinafter, a part of the first elastic member (210)formed between the pair of adjacent cut-out units (214) is defined as acoupling unit (215).

The coupling unit (215) formed by the cut-out units (214) by insertionof the boss (132) of the bobbin (150) into the through hole (212) of thefirst elastic member (210) formed with the cut-out units (214) generatesan elastic deformation to be coupled to the periphery of the boss (132)of the bobbin (150). The coupling unit (215) of the first elastic member(210) is secured at a corner area, where the boss (132) of the bobbin(150) and the planar surface (134 b) of the disengagement preventionunit (134) meet, through formation of the disengagement prevention unit(134) at an upper end of the boss (132) of the bobbin (150) by applyingheat and pressure to the upper end of the boss (132) of the bobbin (150)after the boss (132) of the bobbin (150) is coupled by the first elasticmember (210). As a result, the first elastic member (210) is tightlybrought into contact with the bottom surface (130) of the bobbin (150)by the coupling unit (215) of the first elastic member (210).

FIG. 5 is a cross-sectional view illustrating a first elastic member anda boss of a VCM according to another exemplary embodiment of the presentdisclosure.

The VCM according to the exemplary embodiment of the present disclosurehas a substantially same configuration as that of the VCM illustrated inFIGS. 1 through 4 except for the disengagement prevention unit and thefirst elastic member, such that explanations that duplicate one anotherwill be omitted, and the same reference numerals will be assigned to thesame elements in the explanations of the figures.

Referring to FIGS. 4 and 5, the coupling unit (215) formed by thecut-out units (214) by insertion of the boss (132) of the bobbin (150)into the through hole (212) of the first elastic member (210) formedwith the cut-out units (214) generates an elastic deformation to becoupled to the periphery of the boss (132) of the bobbin (150).

The upper end of the boss (132) of the bobbin (150) is formed with thedisengagement prevention unit (134) having a larger area than that ofthe boss (132) of the bobbin (150) as the coupling unit (215) is coupledto the periphery of the boss (132) of the bobbin (150), and heat andpressure are applied to the upper end of the boss (132) of the bobbin(150).

In the exemplary embodiment of the present disclosure, a distal end ofthe coupling unit (215) coupled to the periphery of the boss (132) ofthe bobbin (150) is inserted into the disengagement prevention unit(134) at a predetermined depth, whereby the first elastic member (210)is securely fixed at the interior of the disengagement prevention unit(134).

As the coupling unit (215) of the first elastic member (210) is fixedlyinserted into the disengagement prevention unit (134), the first elasticmember (210) is prevented from being disengaged from the bottom surfaceof the bobbin (150) to accurately control a moving distance of thebobbin (150).

FIG. 6 is a cross-sectional view illustrating a first elastic member anda boss of a VCM according to still another exemplary embodiment of thepresent disclosure.

The VCM according to the exemplary embodiment of the present disclosurehas a substantially same configuration as that of the VCM illustrated inFIGS. 1 through 4 except for the disengagement prevention unit and thefirst elastic member, such that explanations that duplicate one anotherwill be omitted, and the same reference numerals will be assigned to thesame elements in the explanations of the figures.

Referring to FIGS. 4 and 6, as the cylindrical boss (132) of the bobbin(150) is inserted into the through hole (212) of the first elasticmember (210) formed with the cut-out units (214), the coupling unit(215) formed by the cut-out units (214) generates an elastic deformationto be coupled to the periphery of the boss (132) of the bobbin (150).The coupling unit (215) is inserted into the boss (132) of the bobbin(150) in a crooked shape relative to the first elastic member (210).

After the coupling unit (215) is coupled to the periphery of the boss(132) of the bobbin (150), the upper end of the boss (132) of the bobbin(150) is coated with adhesive, and the adhesive is cured by heat ofultraviolet to allow a disengagement prevention unit (136) having alarger area than that of the boss (132) of the bobbin (150) to be formedat the upper end of the boss (132) of the bobbin (150). In the exemplaryembodiment of the present disclosure, the adhesive forming thedisengagement prevention unit (136) may include an ultraviolet curingadhesive that is cured by ultraviolet, or a thermally curable adhesivethat is cured by heat.

The disengagement prevention unit (136) formed by the adhesive includesa round-headed curvature unit (136 a), and a planar unit (136 b)connected to the curvature unit (136 a), and the coupling unit (215) ofthe first elastic member (210) is arranged at a place where the planarunit (136 b) of the disengagement prevention unit (136) and theperiphery of the boss (132) of the bobbin (150) meet.

As the coupling unit (215) of the first elastic member (210) is fixed ata place where the planar unit (136 b) of the disengagement preventionunit (136) and the periphery of the boss (132) of the bobbin (150) meet,the first elastic member (210) is prevented from being disengaged fromthe bottom surface (130) of the boss (132) of the bobbin (150) toaccurately control a moving distance of the bobbin (150).

FIG. 7 is a cross-sectional view illustrating a first elastic member anda boss of a VCM according to still another exemplary embodiment of thepresent disclosure.

The VCM according to the exemplary embodiment of the present disclosurehas a substantially same configuration as that of the VCM illustrated inFIG. 6 except for the disengagement prevention unit and the firstelastic member, such that explanations that duplicate one another willbe omitted, and the same reference numerals will be assigned to the sameelements in the explanations of the figures.

Referring to FIGS. 4 and 7, as the cylindrical boss (132) of the bobbin(150) is inserted into the through hole (212) of the first elasticmember (210) formed with the cut-out units (214), the coupling unit(215) formed by the cut-out units (214) generates an elastic deformationto be coupled to the periphery of the boss (132) of the bobbin (150).The coupling unit (215) is inserted into the boss (132) of the bobbin(150) in a crooked shape relative to the first elastic member (210).

After the coupling unit (215) is coupled to the periphery of the boss(132) of the bobbin (150), the upper end of the boss (132) of the bobbin(150) is coated with adhesive, and the adhesive is cured by heat ofultraviolet to allow a disengagement prevention unit (136) having alarger area than that of the boss (132) of the bobbin (150) to be formedat the upper end of the boss (132) of the bobbin (150). In the exemplaryembodiment of the present disclosure, the adhesive forming thedisengagement prevention unit (136) may include an ultraviolet curingadhesive that is cured by ultraviolet, or a thermally curable adhesivethat is cured by heat.

The disengagement prevention unit (136) formed by the adhesive includesa round-headed curvature unit (136 a), and a planar unit (136 b)connected to the curvature unit (136 a), and at least a part of thecoupling unit (215) of the first elastic member (210) is inserted intothe disengagement prevention unit (136). To be more specific, thecoupling unit (215) of the first elastic member (210) is inserted intothe disengagement prevention unit (136) while uncured adhesive is coatedon the boss (132) of the bobbin (150) or adhesive is being cured.

As the coupling unit (215) of the first elastic member (210) is insertedinto the disengagement prevention unit (136), the first elastic member(210) is prevented from being disengaged from the bottom surface (130)of the boss (132) of the bobbin (150) to accurately control a movingdistance of the bobbin (150) mounted with the lens.

FIG. 8 is a plane view illustrating a first elastic member of a VCMaccording to still another exemplary embodiment of the presentdisclosure, FIG. 9 is a cross-sectional view illustrating a firstelastic member and a heat-fused disengagement prevention unit of FIG. 8,and FIG. 10 is a cross-sectional view illustrating a disengagementprevention unit formed with a boss coupled to the first elastic memberand an adhesive of FIG. 8.

The VCM according to still another exemplary embodiment of the presentdisclosure has a substantially same configuration as that of the VCMillustrated in FIGS. 1 through 6 except for the first elastic member,such that explanations that duplicate one another will be omitted, andthe same reference numerals will be assigned to the same elements in theexplanations of the figures.

Referring to FIGS. 8, 9 and 10, the first elastic member (210) includesthe through hole (212) coupled to the boss (132) of the bobbin (150)formed at the bottom surface (130) of the bobbin (150). In the exemplaryembodiment of the present disclosure, a diameter of the through hole(212) is formed to be greater than that of the boss (132) of the bobbin(150), such that a space is formed between the inner lateral surface(212 a) of the first elastic member (210) formed by the through hole(212) and the periphery of the boss (132) of the bobbin (150).

A plurality of coupling units (216) is protruded, each at apredetermined gap, from the inner lateral surface (212 a) of the firstelastic member (210) formed by the through hole (212), and a length ofeach coupling unit (216) is formed to be longer than a differencebetween the diameter of the through hole (212) and the diameter of theboss (132) of the bobbin (150). As a result, as the boss (132) of thebobbin (150) is coupled to the through hole (212), the periphery of theboss (132) of the bobbin (150) is elastically arranged with theplurality of coupling units (216) each protruded from the inner lateralsurface (212 a) of the first elastic member (210).

Referring to FIG. 9, after the coupling units (216) formed at the firstelastic member (210) are arranged at the periphery of the boss (132) ofthe bobbin (150), the upper end of the boss (132) of the bobbin (150) isdeformed by heat and pressure to form a disengagement prevention unit(134) at the boss (132) of the bobbin (150), and a place, where a planarunit (134 b) of the disengagement prevention unit (134) and theperiphery of the boss (132) of the bobbin (150) meet, is arranged withthe coupling units (216) of the first elastic member (210) to allow thefirst elastic member (210) to be tightly brought into contact with thebottom surface (130) of the bobbin (150). Alternatively, when thedisengagement prevention unit (134) is formed at the boss (132) of thebobbin (150), a part of the coupling units (216) of the first elasticmember (210) may be inserted into the disengagement prevention unit(134).

Meanwhile, as illustrated in FIG. 10, after the coupling units (216)formed at the first elastic member (210) is arranged to the periphery ofthe boss (132) of the bobbin (150), the upper end of the boss (132) ofthe bobbin (150) is coated with adhesive, and the adhesive is cured byheat of ultraviolet to allow a disengagement prevention unit (136) to beformed at the boss (132) of the bobbin (150), and a place, where aplanar unit (134 b) of the disengagement prevention unit (136) and theperiphery of the boss (132) of the bobbin (150) meet, is arranged withthe coupling units (216) of the first elastic member (210).Alternatively, when the disengagement prevention unit (136) is formed atthe boss (132) of the bobbin (150), a part of the coupling units (216)of the first elastic member (210) may be inserted into the disengagementprevention unit (136).

Referring to FIG. 1 again, the second elastic member (220) is coupled tothe upper surface (120) of the bobbin (150), and the bobbin (150)mounted with the coil block (190) is elastically supported by the firstand second elastic members (210, 220).

As apparent from the foregoing, the elastic member is prevented frommoving from the bobbin by the gap formed between the bobbin and theelastic member elastically supporting the bobbin to thereby accuratelycontrol a distance between the lens mounted on the bobbin and the imagesensor.

FIG. 11 is an exploded perspective view of a VCM according to anexemplary embodiment of the present disclosure, FIG. 12 is across-sectional view of a VCM illustrated in FIG. 11, FIG. 13 is a planeview illustrating a rear surface of a bobbin of FIG. 11, FIG. 14 is aplane view illustrating a first elastic member of FIG. 11 and FIG. 15 isa cross-sectional view illustrating a state in which the bobbin and thefirst elastic member of FIG. 11.

Referring to FIGS. 11 through 15, a VCM (800) includes a rotor (100), anelastic member (200), a stator (300), a reinforcement member (500, seeFIG. 5) and a case (400). The VCM (800) may further include a base plate(600) and a spacer (700). The rotor (100) includes a bobbin (150) and acoil block (190).

Referring to FIGS. 12 and 13, the bobbin (150) includes a bobbin body(110), a coupling boss (120 a) and a recess (125). The bobbin body (110)takes the shape of a hollow holed cylinder for accommodating a lenstherein, for example. The cylindrical bobbin body (110) includes anupper surface (116) and a bottom surface (117) opposite to the uppersurface (116).

An inner surface of the bobbin body (110) for accommodating the lens isformed with a female screw unit (112) to which a lens fixing member (notshown) is coupled, and the lens fixing member is coupled to the lens.Alternatively, it should be also appreciated that the lens is directlycoupled to the female screw unit (112) of the bobbin body (110).

A peripheral bottom distal end of the bobbin body (110) is formed with ahitching sill (115) for supporting a coil block (190, described later).

Referring to FIG. 13, the coupling boss (120 a) is protruded from thebottom surface (117) of the bobbin body (110) to fix first elasticmembers (210, described later) of the elastic member (200). Fourcoupling bosses (120 a) are formed at four corners of the bobbin body(110), each formed at an equidistance on the bottom surface of thebobbin body (110) to be stably coupled to the first elastic member(210).

Referring to FIG. 15, after the first elastic member (210) is coupled tothe bottom surface (117) of the bobbin (150), each distal end of thecoupling bosses (120 a) is thermally fused to prevent the first elasticmember (210) from being disengaged from the bobbin (150), whereby thedistal end of the coupling boss (120 a) is formed with a head unit (123)greater than the original coupling boss (120 a) size-wise.

Referring to FIG. 13 again, the recess (125) is adjacently formed witheach coupling boss (120 a) at the bottom surface of the bobbin body(110), and the first elastic members (210, described later) are securedto the bottom surface of the bobbin (150) along with the coupling boss(120 a)

In the exemplary embodiment of the present disclosure, the recess (125)is adjacently formed with a distal end of the first elastic members(210, described later). The reason that the recess (125) is adjacentlyformed with a distal end of the first elastic members (210) is because aforce to lift the first elastic member (210) from the bobbin (150) isapplied to the first elastic member (210) when the bobbin (150) isvertically operated.

The coil block (190) is arranged on the hitching sill (115) formed onthe bobbin (150), and takes the shape of a cylinder wound with a coil,for example. The coil block (190) may be secured to the hitching sill(115) of the bobbin (150) and/or to the periphery of the bobbin (150)using an adhesive, and the coil forming the coil block (190) iselectrically connected to the first elastic member (210) of a leafspring (200, described later).

Referring to FIGS. 11 and 12 again, the stator (300) includes a yoke(310) and a magnet (350). The yoke (310) includes an upper plate (312),a lateral plate (314) and a yoke unit (316). The yoke (310) serves toprevent the magnetic flux generated from the magnet (350, describedlater) from leaking to the outside of the yoke (310).

The upper plate (312) of the yoke (310) may take the shape of a squareplate, when viewed from a top plan view, and is centrally formed with acircular opening for exposing the upper distal end of the bobbin (150).

The lateral plate (314) is extended to a direction parallel with theperiphery of the bobbin (150) from four edges of the upper plate (312),and integrally formed with the four edges of upper plate (312). The yokeunit (316) is protruded from an inner lateral surface of the upper plate(312) formed by the circular opening of the upper plate (312) to adirection facing the bottom distal end of the bobbin (150), where theyoke unit (316) and the lateral plate (314) are mutually arranged inparallel. The yoke unit (316) is inserted into a space formed by thebobbin (150) and the coil block (190). The yoke unit (316) furtherenhances a driving efficiency of the rotor (100) by causing the magneticflux generated from the coil block (190) to face the magnet (350).

The magnets (350) are arranged at an inner space formed by the upperplate (312) of the yoke (310) and the lateral plate (314). Each magnet(350) is arranged opposite to the coil block (190).

The bobbin (150) is moved upwards by a force generated by magnetic fieldgenerated by the magnets (350) and a magnetic field generated by thecoil block (190), and the moved bobbin (150) is elastically supported bythe elastic members (200, described later). At this time, a moveddistance of the bobbin (150) can be accurately adjusted by a currentapplied to the coil block (190).

Referring to FIGS. 11, 12 and 14 again, the elastic member (200)includes first and second elastic members (210, 220). The first elasticmember (210) is elastically coupled to the bottom surface (117) of thebobbin (150), and the second elastic member (220) is elastically coupledto the upper surface (116) of the bobbin (150).

Two first elastic members (210) may be formed, for example, and each ofthe first elastic members (210) is symmetrically formed to be coupled tothe bottom surface (117) of the bobbin (150). Meanwhile, one secondelastic member (220) may be formed, for example.

Each of the two first elastic members (210) is formed by processing ametal plate having a thin thickness, and the two first elastic members(210) having an electrical conductivity is electrically connected to thecoil of the coil block (190).

A driving signal applied from outside is supplied to the coil block(190) through the two first elastic members (210), and a magnetic fieldis generated from the coil block (190).

Referring to FIGS. 13 and 14, each of the first elastic members (210)includes an external leaf spring unit (211), and an inner leaf springunit (213) and a connection spring (215) elastically connecting theexternal leaf spring unit (211) and the inner leaf spring unit (213).

Both distal ends of the inner leaf spring unit (213) of the firstelastic member (210) are formed with a first through hole (216 a) and asecond through hole (217). The first through hole (216 a) is formed atboth distal ends of the inner leaf spring unit (213) in opposition tothe coupling boss (120 a) of the bobbin (150) and inserted into thecoupling boss (120 a) of the bobbin (150).

In a case the first through hole (216 a) of the inner leaf spring unit(213) is inserted into the coupling boss (120 a) of the bobbin (150),the inner leaf spring unit (213) is arranged on the bottom surface (117)of the bobbin (150). After the first through hole (216 a) of the innerleaf spring unit (213) is inserted into the coupling boss (120 a) of thebobbin (150), and heat and pressure are applied to the coupling boss(120 a), the distal end of the coupling boss (120 a) is formed with ahead unit (123) that is greater than the first through hole (216 a)size-wise by thermal fusing process and fused into the inner leaf springunit (213).

The second through hole (217) is formed at both distal ends of the innerleaf spring unit (213) in opposition to the recess (125) of the bobbin(150) to expose the recess (125) to the outside of the first elasticmember (210).

In the exemplary embodiment of the present disclosure, after the firstthrough hole (216 a) of the first elastic member (210) is coupled by thecoupling boss (120 a) of the bobbin (150), the second through hole (217)of the first elastic member (210) and the recess (125) formed on thebottom surface (117) of the bobbin (150) corresponding to the secondthrough hole (217) are employed to mutually couple the first elasticmember (210) and the bobbin (150).

Referring to FIG. 15 again, the reinforcement member (500) is arrangedon the second through hole (217) of the first elastic member (210) andthe recess (125) of the bobbin (150) to reinforce the coupling strengthbetween the bobbin (150) and the first elastic member (210) along withthe coupling boss (120 a) and the first through hole (216 a), wherebydurability of the VCM (800) can be enhanced.

The reinforcement member (500) according to the exemplary embodiment ofthe present disclosure includes an adhesive, and if a fluid adhesive isprovided into the recess (125) of the bobbin (150) through the secondthrough hole (217), the fluid adhesive fills an empty space formed bythe recess (125) of the bobbin (150) and the second through hole (217)through capillary phenomenon, and as shown in FIG. 15, the fluidadhesive is spread to a gap between the first elastic member (210) andthe bottom surface (117) of the bobbin (150) through the capillaryphenomenon to greatly increase a contact area between the first elasticmember (210) and the bottom surface (117) of the bobbin (150).

In a case the fluid adhesive is filled in the second through hole (217)and the recess (125) of the bobbin (150), the adhesive is cured to formthe reinforcement member (500) connecting the recess (125) of the bobbin(150) and the second through hole (217). In the exemplary embodiment ofthe present disclosure, the adhesive may include a thermally curableadhesive.

Referring to FIGS. 11 and 12 again, the case (400) includes an uppercase (410) and a bottom case (420). The upper case (410) includes anupper plate (411) and a coupling pillar (412). The upper case (410) isarranged on an upper surface of the yoke (310), and the second elasticmember (220) of the leaf spring is interposed between the upper plate(411) of the upper case (410) and the yoke (310).

The upper plate (411) of the upper case (410) takes the shape of asquare plate, when viewed from a top plan view, and is centrally formedwith a circular opening (414) for exposing the bobbin (150).

The coupling pillar (412) is protruded in parallel with the bobbin (150)from four corners of the upper plate (411), and is coupled to the bottomcase (420, described later). The bottom case (420) includes a floorplate (421) and a coupling pillar (424). The floor plate (421) takes theshape of a plate and is centrally formed with a circular opening (422).

The floor plate (421) is formed with pillars (424) coupled to eachcoupling pillar (412) of the upper case (410). The coupling pillar (412)of the upper case (410) and the coupling pillar (421) of the bottom case(420) may be coupled by way of half lap-joint method, for example.

The floor plate (421) of the bottom case (420) is arranged thereon withthe outer leaf spring unit (211) of the first elastic member (210)coupled to the bottom surface (130) of the bobbin (150). The uppersurface of the outer leaf spring unit (211) of the first elastic member(210) is arranged thereon with a square-framed spacer (700) to cause theouter leaf spring unit (211) of the first elastic member (210) to beinterposed between the floor plate (421) of the bottom case (410) andthe spacer (700).

FIG. 16 is a cross-sectional view illustrating a state in which a bobbinand a first elastic member of a VCM according to another exemplaryembodiment of the present disclosure.

The VCM according to still another exemplary embodiment of the presentdisclosure has a substantially same configuration as that of the VCMillustrated in FIG. 15 except for the reinforcement member, such thatexplanations that duplicate one another will be omitted, and the samereference numerals will be assigned to the same elements in theexplanations of the figures.

Referring to FIG. 16, the reinforcement member (500) of the VCM (800) isinserted into the recess (125) of the bobbin (150) through the secondthrough hole (217) of the first elastic member (210) to reinforce thecoupling strength between the bobbin (150) and the first elastic member(210) along with the coupling boss (120 a), whereby durability of theVCM (800) can be increased.

The reinforcement member (500) according to another exemplary embodimentof the present disclosure includes a screw body (510) and a fasteningmember including a head unit (520). The periphery of the screw body(510) is formed with a screw thread, and is screwed to an inner lateralsurface formed by the recess (125) of the bobbin (150).

The head unit (520) is formed to be larger than the second through hole(217) size-wise, and in a case the screw body (510) is coupled to therecess (125) of the bobbin (150), the head unit (520) is brought intocontact with the bottom surface of the first elastic members (210)opposite to the bottom case (420) to prevent the first elastic members(210) from being disengaged from the bobbin (150).

FIG. 17 is a cross-sectional view illustrating a state in which a bobbinand a first elastic member of a VCM according to still another exemplaryembodiment of the present disclosure.

The VCM according to still another exemplary embodiment of the presentdisclosure has a substantially same configuration as that of the VCMillustrated in FIG. 15 except for the reinforcement member, such thatexplanations that duplicate one another will be omitted, and the samereference numerals will be assigned to the same elements in theexplanations of the figures.

Referring to FIG. 17, the reinforcement member (500) of the VCM (800) isinserted into the recess (125) of the bobbin (150) through the secondthrough hole (217) of the first elastic member (210) to reinforce thecoupling strength between the bobbin (150) and the first elastic member(210) along with the coupling boss (120 a), whereby durability of theVCM (800) can be increased.

The reinforcement member (500) according to another exemplary embodimentof the present disclosure includes a body (510) and a coupling pinincluding a head unit (520). The body (510) is press-fitted into therecess (125) of the bobbin (150). The head unit (520) is formed to belarger than the second through hole (217) size-wise, and in a case thescrew body (510) is coupled to the recess (125) of the bobbin (150), thehead unit (520) is brought into contact with the bottom surface of thefirst elastic members (210) opposite to the bottom case (420) to preventthe first elastic members (210) from being disengaged from the bobbin(150).

As apparent from the foregoing, the VCM according to the presentdisclosure has an advantageous effect in that the bottom end of thebobbin is formed with a coupling boss and a recess, a first through holeis formed opposite to the coupling boss among the first elastic memberscoupled to the bottom end of the bobbin and inserted into the couplingboss, a second through hole is formed opposite to the recess among thefirst elastic members, a distal end of the coupling member is thermallyfused, and the second coupling hole and the recess are filled with thereinforcement member to reinforce the coupling strength between thebobbin and the first elastic members, whereby the first elastic membersare prevented from being disengaged to increase the durability and toreduce the manufacturing cost.

FIG. 18 is an exploded perspective view of a VCM according to anexemplary embodiment of the present disclosure, FIG. 19 is a plane viewillustrating a first elastic member of FIG. 17, FIG. 20 is a rearperspective view illustrating the bobbin and the first elastic member ofthe elastic member of FIG. 17, and FIG. 21 is a partially enlarged viewof ‘A’ of FIG. 20.

Referring to FIG. 18, a VCM (800) includes a rotor (100), an elasticmember (200), and a stator (300). The VCM (800) may further include aspacer (700). Referring to FIGS. 18 and 19, the rotor (100) includes abobbin (150) and a coil block (190).

The bobbin (150) may take the shape of a cylinder with both ends opened.The both ends-opened cylindrical bobbin (150) serves to accommodate andsecure a lens. In the exemplary embodiment of the present disclosure,the bobbin (150) takes the shape of a cylinder with both ends opened,for example.

An inner surface of the bobbin (150) is formed with a female screw unit(112) for accommodating the lens, and the lens is secured by using thefemale screw (112). The lens may be secured to the female screw unit(112) of the bobbin (150) using the lens fixing member. Alternatively,it should be also appreciated that the lens is directly coupled to thefemale screw unit (112) of the bobbin body (110).

A peripheral bottom distal end of the bobbin body (110) is formed with ahitching sill (115) for supporting a coil block (190, described later).

Referring to FIG. 20, the bottom surface of the bobbin is symmetricallyformed with bosses (132) based on the bobbin (150). The bosses (132)formed at the bottom surface (130) of the bobbin (150) serves toaccommodate the bobbin (150) to a bottom case (or base, 420) of a case(400, described later).

The bosses (132) formed at the bottom surface (130) of the bobbin (150)may take the shape of a cuboid. Alternatively, the bosses (132) formedat the bottom surface (130) of the bobbin (150) may take various shapesother than the cuboid. Both sides of the boss (132) formed at the bottomsurface (130) of the bobbin (150) may be formed with pillar-shapedcoupling bosses (130 a).

The coupling bosses (130 a) are coupled to the first elastic member(210) of elastic member (200, described later) to serve to tightlycontact the elastic member (200) to the bottom surface (130) of thebobbin (150). A distal end of the coupling boss (130 a) is thermallyfused by heat and pressure to tightly bring the first elastic member(210) to the bottom surface (130).

The bottom surface (130) of the bobbin (150) is additionally formed witha fusion unit (139) along with the coupling boss (130 a). In theexemplary embodiment of the present disclosure, the fusion unit (139)may take the shape of a cuboidal pillar, for example. Alternatively, thefusion unit (139) may take various shapes including a circular cylinder,a square pillar, and a polygonal pillar other than the cuboidal pillar.

The fusion unit (139) formed on the bottom surface (130) of the bobbin(150) is formed at a center of an adjacent pair of bosses (132) of thebobbin (150). The fusion unit (139) is arranged at a positioncorresponding to that of a distal end opposite to the pair of firstelastic members (200, described later). The fusion unit (139) serves totightly bring the distal end of the first elastic members (210) of theelastic member (200) to the bottom surface (130) of the bobbin (150).

In the exemplary embodiment of the present disclosure, the fusion unit(139) is lower than the boss (132) of the bobbin (150) when the heightof the fusion unit (139) is measured from the bottom surface (130) ofthe bobbin (150).

If the fusion unit (139) is higher than the boss (132) of the bobbin(150), the fusion unit (139) may be brought into contact with the bottomcase (420) before the boss (132) of the bobbin (150) to incline thebobbin (150) when the bobbin (150) is accommodated into the case (400).

The coil block (190) is wound on the periphery of the bobbin (150), andis secured to the hitching sill (115) formed on the bottom peripheralsurface of the bobbin (150). The coil block (190) may be secured to thehitching sill (115) of the bobbin (150) and/or to the periphery of thebobbin (150) using an adhesive. The coil block (190) may be bonded tothe periphery of the bobbin (150) using an adhesive, for example.Alternatively, it should be apparent that the cylindrically wound coilblock (190) is inserted into the periphery of the bobbin (150), andcoupled to the bobbin (150) using an adhesive.

As a driving signal is applied to the coil block (190) arranged on theperiphery of the bobbin (150), a magnetic field is generated, and thebobbin (150) is driven by the magnetic field generated by the coil block(190) and the magnetic field generated by the magnet (350) of the stator(300)

Referring to FIGS. 18 and 19, the elastic member (200) includes a firstelastic member (210) and a second elastic member (220). The firstelastic member (210) is coupled to the bottom surface (130) of thebobbin (150) to elastically support the bobbin (150).

In the exemplary embodiment of the present disclosure, the first elasticmember (210) is formed in a pair and each of the first elastic members(210) is coupled to the bottom surface (130) of the bobbin (150), whereone of the pair of first elastic members (210) is electrically insulatedfrom the other.

Each of the pair of first elastic members (210) is formed with aconnection terminal (211) to which a driving signal is applied fromoutside. Each of the pair of first elastic members (210) includes anouter elastic unit (212), an inner elastic unit (214) and a connectionelastic unit (219).

The outer elastic unit (212) and the inner elastic unit (214) areconnected by the connection elastic unit (219), and each of the pair offirst elastic members (210) elastically supports the bobbin (150) usingthe elastic force of the connection elastic unit (219).

The outer elastic unit (212) is secured by the bottom case (420) of thecase (400, described later) and the spacer (700), and the inner elasticunit (214) is secured to the bottom surface (130) of the bobbin (150).The outer elastic unit (212) is formed with the connection terminal(211) electrically connected to an outside circuit board.

The inner elastic unit (214) is soldered to a distal end of the coilforming the coil block (190) using a solder. The inner elastic unit(214) is formed with a clip unit for being coupled to the coil of thecoil block (190). The inner elastic unit (214) is formed in a shape of acurved plate having a substantially same curvature as that of the bottomsurface (130) of the bobbin (150). Thus, a driving signal applied to theconnection terminal (211) from outside is applied to the coil block(190) sequentially through the outer elastic unit (212), the innerelastic unit (214) and the connection elastic unit (219), whereby amagnetic field is generated from the coil block (190).

The inner elastic unit (214) includes a through hole (215), which isformed at a place coupled to the coupling boss (130 a) formed at thebottom surface (130) of the bobbin (150) illustrated in FIG. 3.

As the pair of first elastic members (210) is arranged along the bottomsurface (130) of the bobbin (150), each distal end of inner elasticunits of the pair of first elastic members (210) faces the other distalend when viewed in a top plan view. Each distal end of inner elasticunits of the pair of first elastic members (210) is arranged across thefusion unit (139), and each distal end of the inner elastic units (214)is secured by the fusion unit (139).

In a case each distal end of the inner elastic units (214) is secured bythe fusion unit (139), the distal ends of the inner elastic units (214)are distanced from the bobbin (150) to prevent the coil of the coilblock (19) from being short-circuited by the inner elastic unit (214),even if the VCM (800) is applied with a strong shock or vibration.

Referring to FIGS. 20 and 21, each distal end facing the inner elasticunit (214) of the first elastic members (210) may be formed with aconcave coupling groove (210 a) in order to secure, by the fusion unit(139), the distal ends facing the first elastic members (210) to thebottom surface (130) of the bobbin (150).

The concave coupling groove (210 a) formed at each distal end facing theinner elastic unit (214) of the first elastic members (210) takes theshape of a groove or an opening inserted to the surface of the fusionunit (139).

In a case the fusion unit takes the shape of a cuboidal pillar, forexample, the coupling groove (210 a) may take the shape of encompassingthree lateral surfaces of the fusion unit (139), and the inner elasticunit (214) of the first elastic members (210) may be securely coupled tothe bottom surface (130) of the bobbin (150) by the coupling groove (210a).

Although the exemplary embodiment of the present disclosure hasexplained and illustrated the fusion unit formed at the bobbin (150),and fusion of the first elastic members (210) using the fusion unit, theconfiguration is not limited thereto. For example, the distal endsfacing the first elastic members (210) may be directly fused to thebottom surface (130) of the bobbin (150) in order to prevent the coil ofthe coil block (190) from being short-circuited.

Referring to FIG. 18 again, the second elastic member (220) of theelastic member (200) is secured to a yoke (310, described later), and iselastically secured to an upper surface (120) facing the bottom surface(130) of the bobbin (150).

The stator (300) includes a yoke (310) and a magnet (350). The yoke(310) includes a yoke upper plate (312), a yoke lateral plate (314) anda back yoke (316). In the exemplary embodiment of the presentdisclosure, the yoke (310) serves to enhance a driving efficiency of therotor (100) in order to prevent the magnetic field generated by themagnet (350, described later) from leaking.

The yoke upper plate (314) takes the shape of a rectangular plate, andis centrally formed with an opening for exposing a bobbin or a lens. Theyoke lateral plate (314) is extended from each edge to a directionencompassing the bobbin (150). The back yoke (316) is extended from aninner lateral surface of the yoke upper plate (312) to face each cornerof the yoke lateral plate (314).

The magnet (350) is arranged at a place opposite to each corner of theyoke lateral plate (314), and is arranged at a place opposite to thecoil block (190) arranged on the periphery of the bobbin (150). Themagnet (350) may be bonded to the yoke lateral plate (314) using anadhesive, for example.

The bobbin (150) is moved upwards by a force generated by magnetic fieldgenerated by each of the magnets (350) and a magnetic field generated bythe coil block (190), and the bobbin (150) is elastically supported byfirst and second elastic members (210, 220). At this time, a moveddistance of the bobbin (150) can be accurately adjusted by a currentapplied to the coil block (190).

A case (400) includes an upper case (410) and a bottom case (420). Thecase (400) serves to mutually couple and secure the rotor (100), theelastic member (200) and the stator (300). The upper case (410) includesan upper plate (411) and a coupling pillar (412). The upper case (410)is arranged on an upper surface of the yoke (310), and the secondelastic member (220, described later) in the elastic member (200) isinterposed between the upper case (410) and the yoke (310).

The upper plate (411) of the upper case (410) takes the shape of asquare plate when viewed from a top plan view, and is centrally formedwith a circular opening (414) for exposing the bobbin (150).

The coupling pillar (412) of the upper case (410) is protruded inparallel with the bobbin (150) from four corners of the upper plate(411), and is coupled to the bottom case (420, described later). Thebottom case (420) includes pillars (425) coupled to each coupling pillar(412) of the upper case (410).

As apparent from the foregoing, a distal end of leaf spring elasticallysupporting the bobbin is securely coupled to the bobbin using thermalfusion method to prevent the coil of the coil block from beingshort-circuited from the leaf spring even if the VCM is applied with astrong shock or vibration.

FIG. 22 is a partially cut-out perspective view of a VCM according to anexemplary embodiment of the present disclosure, FIG. 23 is a perspectiveview illustrating the bobbin and elastic member of FIG. 22, FIG. 24 is apartially enlarged view of ‘A’ of FIG. 22, and FIG. 25 is across-sectional view illustrating a process in which a bobbin and anelastic member are bonded.

Referring to FIGS. 22 through 25, the VCM (800) may include a rotor(113), a base (114), a stator (131), a spacer (140) and elastic members(151, 155). The VCM may further include an upper spacer (160) and acover can (170).

The rotor (113) may include a bobbin (118) coupled by a lens (not shown)and a coil (119). The rotor (113) serves to adjust a gap between animage sensor module arranged at the rear surface of the base (114) andthe lens coupled to the bobbin (118).

The bobbin (118) may take the shape of cylinder, for example, and isformed with an inner lateral surface for adequately coupling adisk-shaped lens. The inner lateral surface of the bobbin (118) isformed with a screw unit for coupling the lens.

The bobbin (118) is externally formed with two hitching sills (111, 111a), and the hitching sill (111) formed at the bottom surface is arrangedwith a coil, and the hitching sill (111 a) formed on the upper surfaceis arranged thereon with a part of the yoke of the stator (130,described later).

A bottom surface (118 a) opposite to the base (114) in the bobbin (118)is formed with a plurality of lugs (117 a). The lugs (117 a) serve ascoupling members that are coupled to the elastic member (151, describedlater), and the bottom surface (118 a) of the bobbin (118) and an uppersurface of the base (114) are distanced at a predetermined gap by thelugs (117 a).

An upper surface (118 b) of the bobbin (118) facing the bottom surface(118 a) of the bobbin (118) is formed with adhesive guide lugs (118 c).The adhesive guide lugs (118 c) are formed in a pair, and each adhesiveguide lug is adjacently arranged to the other lug, and is adjacentlyarranged to an inner lateral surface of the bobbin (118) in the uppersurface (118 b) of the bobbin (118).

The pair of adhesive guide lugs (118 c) is intermittently arranged alongthe upper surface (118 b) of the bobbin (118), and may be formed at anequidistant gap.

The coil (119) formed by a wire coated with insulation resin such asenamel resin is wound on the periphery of the bobbin (118) in acylindrical shape. Alternatively, the cylindrically wound coil (119) maybe secured to the periphery of the bobbin (118) using an adhesive. Abottom end of the coil (119) is arranged on the hitching sill (111).

An upper end of the cylindrically formed coil (119) is arranged on aplace higher than the hitching sill (111 a), whereby a space is formedbetween the coil (119) and the periphery of the bobbin (118).

The base (114) may include a floor plate (124) and a lateral plate(126). The floor plate (124) takes the shape of a square plate whenviewed from a top plan view, and is formed with a hitching sill (121).The floor plate (124) is divided into a bottom floor plate (124 a) andan upper floor plate (124 b) by the hitching sill (121).

The bottom floor plate (124 a) is arranged thereon with lugs (117 a) ofthe bobbin (118), and the upper floor plate (124 b) is arranged thereonwith a spacer (140). The lateral plate (126) is formed along edges ofthe floor plate (124), and is substantially vertical to the floor plate(124).

The stator (131) is arranged opposite to the coil (119) of the rotor(113), and serves to vertically move the rotor (113). The stator (131)includes a magnet (133) and a yoke (138).

A plurality of magnets (132) may be arranged about the coil (119), eachat an equidistant gap. A magnetic field generated by the magnet (133)and a magnetic field generated by the coil (119) generate attractiveforce and repulsive force, and the rotor (113) is vertically movedrelative to the stator (131) by the attractive force and repulsiveforce.

The yoke (138) includes an outer yoke unit (137), an inner yoke unit(135) and a connection yoke unit (135 a). In the exemplary embodiment ofthe present disclosure, the yoke (138) includes a metal plate. The yoke(138) prevents or restrains a magnetic field generated by the magnet(133) and a magnetic field generated by the coil (119) from leaking,whereby a driving efficiency of the rotor (113) can be enhanced.

The outer yoke unit (137) includes four plates formed in parallel withthe periphery of the bobbin (118), for example. The inner yoke unit(135) is arranged at a place corresponding to that of each magnet (133).The connection yoke unit (135 a) functions to mutually connect the outeryoke unit (137) and the inner yoke unit (135).

The magnet (133) is accommodated into the yoke (138), and may be bondedto an interior of the yoke (138) using an adhesive. The spacer (140) isinterposed between the magnet (133) and the upper floor plate (124 b) ofthe floor plate (124) of the base (114) to secure the magnet (133) at apredetermined position.

An upper spacer (160) depresses the yoke (138) to place the yoke (138)at a predetermined position. The upper spacer (160) takes the shape of asquare, and depresses the connection yoke unit (135 a) of the yoke (138)to secure the magnet (133) on the spacer (140).

The elastic members (151, 155) elastically support the rotor (113).Hereinafter, the elastic members (151, 155) are defined as a firstelastic member (151) and a second elastic member (155).

The first elastic member (151) including two elastic members is arrangedalong the bottom surface (118 a) of the bobbin (118), and each of thetwo first elastic members (151) is electrically connected therebetween.The first elastic member (151) includes an inner elastic unit, an outerelastic unit and a connection elastic unit.

The inner elastic unit takes the shape of a semi-circular ring, and iscoupled to the lug (117 a) formed at the bottom surface of the bobbin(118).

The outer elastic unit takes the shape of a semi-circular ring, and isinterposed between the upper floor plate (124 b) of the floor plate(124) at the base (114) and the spacer (140). The connection elasticunit elastically connects the inner elastic unit and the outer elasticunit. In the exemplary embodiment of the present disclosure, the innerelastic unit, the outer elastic unit and the connection elastic unit areintegrally formed.

Referring to FIGS. 23 and 24, the second elastic member (155) isarranged on the upper surface (118 b) which is a distal end facing thebottom surface (118 a) of the bobbin (118). The second elastic member(155) includes an inner elastic unit (156), an outer elastic unit (157)and a connection elastic unit (158).

The inner elastic unit (156) takes the shape of a round ring arrangedalong the upper surface (118 b) of the bobbin (118), and the outerelastic unit (157) takes the shape of a round ring having a greaterdiameter than that of the inner elastic unit (156). The connectionelastic unit (158) elastically connects the inner elastic unit (156) andthe outer elastic unit (157), and the rotor (113) including the bobbin(118) is elastically supported to the stator (131) by the outer elasticunit (157).

The outer elastic unit (157) is interposed between the upper spacer(160) and the yoke (138) and secured by the upper spacer (160) and theyoke (138). The inner elastic unit (156) is arranged at a place oppositeto the upper surface (118 b) of the bobbin (118).

The connection elastic unit (158) elastically connects the inner andouter elastic units (156, 157) at four areas, for example, and adhesiveguide lugs (118 c) formed at the upper surface (118 b) of the bobbin(118) are formed at areas where the connection elastic unit (158) andthe inner elastic unit (156) are mutually connected.

In a case the adhesive guide lugs (118 c) are formed at areas where theconnection elastic unit (158) and the inner elastic unit (156) aremutually connected, the adhesive strength of the adhesive at the areaswhere the connection elastic unit (158) and the inner elastic unit (156)are mutually connected can be further enhanced.

Referring to FIGS. 23 and 24 again, the ring-shaped inner elastic unit(156) is formed with an opening (156 a) formed at a place correspondingto that of the adhesive guide lugs (118 c) formed at the upper surface(118 b) of the bobbin (118). The adhesive guide lugs (118 c) areinserted into the opening (156 a) formed at the inner elastic unit(156). Meanwhile, a part of the inner elastic unit (156) is extended toa space formed by the adhesive guide lugs (118 c).

The opening (156 a) formed at the inner elastic unit (156) takes a shapeformed from an inner lateral surface of the inner elastic unit (156) toa direction facing the periphery of the inner elastic unit (156). Thatis, the opening (156 a) formed at the inner elastic unit (156) may takethe shape of the inner elastic unit (156) having an inner lateralsurface opened. Alternatively, the opening (156 a) formed at the innerelastic unit (156) may take the shape of a hole that is closed.

In the exemplary embodiment of the present disclosure, an area of theopening (156 a) formed at the inner elastic unit (156) is formed to belarger than that of each of the adhesive guide lugs (118 c), whereby agap is formed between a lateral surface of the adhesive guide lug (118c) and the lateral surface formed by the opening (156 a) of the innerelastic unit (156). The adhesive is provided between the inner elasticunit (156) and the upper surface (118 b) of the bobbin (118) through thegap.

FIG. 25 is a cross-sectional view illustrating the bobbin, the secondelastic member and a dispenser providing the adhesive of FIG. 24.

Referring to FIGS. 24 and 25, the bobbin (118) and the inner elasticunit (156) are mutually assembled by insertion of the opening formed atthe inner elastic unit (156) of the second elastic member (155) into theadhesive guide lugs (118 c) formed at the upper surface (118 b) of thebobbin (118). Successively, the dispenser (10) provides an adhesive (20)to between the adhesive guide lugs (118 c) formed in a pair, and theadhesive (20) is provided to between the upper surface (118 b) of thebobbin (118) and the inner elastic unit (156) through the gap formedbetween the opening (156 a) of the inner elastic unit (156) and theadhesive guide lugs (118 c).

In a case the dispenser (10) provides a predetermined amount of adhesiveto between the adhesive guide lugs (118 c) and is distanced from theadhesive guide lug (118 c), the adhesive (20) is in a state of beingfilled between both lateral walls facing the adhesive guide lug (118 c),such that the inner elastic unit (156) is not distanced along thedispenser (10) even if the dispenser (10) is distanced from the adhesiveguide lug (118 c), whereby the inner elastic unit (156) of the secondelastic member (155) can be prevented from being deformed or damaged.

Although the exemplary embodiment of the present disclosure hasexplained and illustrated that the upper surface (118 b) of the bobbin(118) and the second elastic member (155) are mutually adhered by usingthe adhesive guide lugs (118 c), the configuration is not limitedthereto. For example, the upper surface (118 b) of the bobbin (118) andthe first elastic member (151) may be mutually adhered by using theadhesive guide lugs.

As apparent from the foregoing, the VCM according to the presentdisclosure has an advantageous effect and industrial applicability inthat adhesive guide lugs are formed at the bobbin coupled to the elasticmember to prevent the elastic member from being deformed and/or damaged.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims.

What is claimed is:
 1. A VCM (voice coil motor), comprising: a base; ayoke disposed over the base; a bobbin disposed in the yoke andcomprising a boss at a lower portion thereof; a coil block arranged at aperiphery of the bobbin; a magnet facing the coil block and fixed to theyoke; and an elastic member comprising a first elastic member coupled toa lower portion of the bobbin and a second elastic member coupled to anupper portion of the bobbin; and a spacer disposed between the firstelastic member and the base, wherein the boss is formed with adisengagement prevention unit preventing the first elastic member frombeing disengaged from the boss.
 2. The VCM of claim 1, wherein thedisengagement prevention unit is integrally formed with the boss bythermal fusion.
 3. The VCM of claim 1, wherein the boss includes a bodyand a head formed at an upper distal end of the body, and wherein thehead of the boss comprises a planar portion and a curved portion.
 4. TheVCM of claim 3, wherein the first elastic member is in direct physicalcontact with the boss, and wherein the planar portion is in directphysical contact with the first elastic member.
 5. The VCM of claim 3,wherein a distance between the planar portion of the head of the bossand the lower portion of the bobbin, measured in a first direction, isshorter than a distance between the curved portion of the boss and thelower portion of the bobbin, measured in the first direction.
 6. The VCMof claim 1, further comprising a reinforcement member arranged at thefirst elastic member.
 7. The VCM of claim 6, wherein the reinforcementmember includes a screw body and a head unit contacting a bottom surfaceof the first elastic member.
 8. The VCM of claim 5, wherein the distancebetween the lower portion of the bobbin and the planar portion of thefirst protrusion, measured in the first direction, is the same as orlarger than a thickness of the first elastic member.
 9. The VCM of claim1, wherein the first elastic member comprises a first inner elasticunit, a first outer elastic unit, and a first connection elastic unit,wherein the second elastic member comprises a second inner elastic unit,a second outer elastic unit, and a second connection elastic unit. 10.The VCM of claim 9, wherein the second elastic member includes aplurality of openings opened toward an inner lateral surface of thebobbin, and the opening of the second inner elastic unit is disposedalong a periphery of the second elastic member.
 11. The VCM of claim 9,wherein one end of the connection elastic unit of the second elasticmember is connected to the inner elastic unit of the second elasticmember at a location between two openings.
 12. The VCM of claim 1,wherein the second elastic member is coupled to the upper portion of thebobbin by an adhesive.
 13. The VCM of claim 3, wherein the head of theboss is integrally formed with the body of the boss by thermal fusion.14. The VCM of claim 3, further comprising an adhesive applied to thehead of the boss.
 15. The VCM of claim 14, wherein the adhesive isfurther disposed between the lower portion of the bobbin and the firstelastic member under the head of the boss.
 16. The VCM of claim 15,wherein the adhesive is a thermally curable adhesive or a UV(Ultraviolet) curable adhesive.
 17. The VCM of claim 9, wherein thebobbin is coupled to the second elastic member where the inner elasticunit of the second elastic member meets the connection elastic unit ofthe second elastic member.
 18. The VCM of claim 1, wherein the coilblock includes distal ends and each distal end of the coil block iselectrically connected to the second elastic member using a solder. 19.A camera module, comprising: the voice coil motor of claim 1; a lensbarrel coupled to the bobbin; an image sensor; and a PCB (PrintedCircuit Board) mounted with the image sensor.
 20. A mobile phone,comprising: the camera module of claim 19; and a controller controllinga distance between a lens mounted on the lens barrel and the imagesensor.